Many substrate treatment processes involve exposing a substrate in a vacuum chamber to an ion beam, thereby causing the substrate to absorb heat. Because the substrate can only absorb a certain amount of heat or reach a certain temperature before being damaged, a common problem encountered is how to cool the wafer during treatment. Typical treatment processes require that substrate temperatures be maintained below 100.degree. C. to be compatible with photoresist.
U.S. Pat. No. 4,949,783, which is assigned to the assignee of the present invention and is incorporated in its entirety herein by reference, is directed to a method and apparatus that employs backside gas to cool a wafer. While the patented technique is quite effective, the apparatus typically employs polymeric seals that have potential for degrading at high temperatures, e.g. greater than about 150.degree. C.
Aside from heat generated as a by product of ion beam processing, it is sometimes desirable actually to supply additional heat to a wafer being processed as well as to cool such heated wafer. Such thermal controlled processing in high vacuum and at high temperatures, e.g. greater than about 150.degree. C., also can cause degradation of polymeric materials such as seals, especially when processing is done for long periods of time.